Treatment of hypercholesterolemia

Plasma exchange in a patient with heterozygous familial hypercholesterolaemia resistant to drug therapy

A 40-year-old male with heterozygous familial hypercholesterolaemia was resistant to combined drug treatment with cholestyramine and nicotinic acid in adequate doses. He had angina pectoris and evidence of three vessel disease in the coronary angiogram. Repeated plasma exchange at intervals of 1-3 weeks simultaneously with combined drug treatment decreased the plasma cholesterol levels by nearly 40%. There were also signs of regression of xanthomata and some improvement of his angina pectoris. No progression of atherosclerosis was seen angiographically after two years treatment. Plasma exchange may be a therapeutic alternative in drug-resistant familial hypercholesterolaemia.

No effect of glucagon-like peptide-1 on short-term satiety and energy intake in man

Centrally administered glucagon-like peptide-1 (GLP-1) inhibits feeding in fasted rats, but its role in human satiety has been largely unexplored. The present study investigated the effect of peripheral GLP-1 infusion on gastric emptying and satiety in man. Ten non-obese male subjects were infused in a randomized single-blind within-subject crossover study using saline infusion as control. They received either a GLP-1 infusion (1·2 pmol/kg per min) or a saline infusion for 1 h, at 18.00 hours. At 20 min after starting the infusion the gastric emptying of a 400 ml water load was measured. Subjects completed behavioural self-rating scales to assess hunger and satiety. After 40 min subjects were given a buffet mealad libitumand their food intake was recorded. GLP-1 infusion raised circulating GLP-1 concentrations to approximately twice those seen following a meal. It did not affect circulating insulin levels but caused a small fall in glucose levels. Gastric emptying of the water load was significantly delayed by the GLP-1 infusion. Energy intake from the buffet was unaffected by GLP-1 infusion. Self-assessment of hunger and satiety was similarly unaffected by the infusion before the buffet meal, although subjects tended to be less hungry after the buffet meal following GLP-1 infusion (P< 0·09). GLP-1 infusion delayed gastric emptying but had a minimal effect on food intake and satiety. This study casts doubts on whether GLP-1 is a major satiety factor in man, although a raised circulating plasma glucose level, as would normally occur postprandially, might be necessary for GLP-1 to increase satiety.

Spreads enriched with plant sterols, either esterified 4,4-dimethylsterols or free 4-desmethylsterols, and plasma total- and LDL-cholesterol concentrations

In a 9-week study seventy-six healthy adult volunteers with an average age of 44 (sd11) years, with baseline plasma total cholesterol levels below 8 mmol/l, received in a balanced, double-blind, crossover design, a total of three different table spreads for personal use. Two spreads were fortified either with free (non-esterified) vegetable-oil sterols, mainly from soyabean oil (31 g sterol equivalents/kg; 0·8 g/d) or sheanut-oil sterols (133 g sterol equivalents/kg; 3·3 g/d). One spread was not fortified (control). Average intake of spread was 25 g/d for 3 weeks. None of the spreads induced changes in blood clinical chemistry or haematology. Plasma total- and LDL-cholesterol concentrations were statistically significantly reduced by 3·8% and 6% (both 0·19 mmol/l) respectively, for the spread enriched with free soyabean-oil sterols compared with the control spread. The spread enriched with sheanut-oil sterols did not lower plasma total- and LDL-cholesterol levels. None of the plant-sterol-enriched spreads affected plasma HDL-cholesterol concentrations. Plasma-lipid-standardized concentrations of α- plus β-carotene were not statistically significantly affected by the soyabean-oil sterol spread in contrast to lipid-standardized plasma lycopene levels which showed a statistically significant decrease (9·5%). These findings indicate that a daily intake of free soyabean-oil sterols as low as 0·8 g added to a spread is effective in lowering blood total- and LDL-cholesterol levels with limited effects on blood carotenoid levels. The lowering in total- and LDL-cholesterol blood levels due to consumption of the vegetable-oil-sterol-enriched spread may be helpful in reducing the risk of CHD for the population.

Hypocholesterolemic effects of crude extract of leaf of Moringa oleifera Lam in high-fat diet fed wistar rats

The leaves of Moringa oleifera Lam (Moringaceae) are used by the Indians in their herbal medicine as a hypocholesterolemic agent in obese patients. The scientific basis for their use in hypercholesterolemia was therefore examined. It was found that administration of the crude leaf extract of Moringa oleifera along with high-fat diet decreased the high-fat diet-induced increases in serum, liver, and kidney cholesterol levels by 14.35% (115-103.2 mg/100 ml of serum), 6.40% (9.4-8.8 mg/g wet weight) and 11.09% (1.09-0.97 mg/g wet weight) respectively. The effect on the serum cholesterol was statistically significant. No significant effect on serum total protein was observed. However, the crude extract increased serum albumin by 15.22% (46-53 g/l). This value was also found to be statistically significant. It was concluded that the leaves of Moringa oleifera have definite hypocholesterolemic activity and that there is valid pharmacological basis for employing them for this purpose in India.

Moderate dose, three-drug therapy with niacin, lovastatin, and colestipol to reduce low-density lipoprotein cholesterol <100 mg/dl in patients with hyperlipidemia and coronary artery disease

The efficacy, safety, and tolerability of a moderate dose, 3-drug lipid-lowering regimen were evaluated among 29 male patients with hyperlipidemia and coronary artery disease. In an initial 12-month phase, regular niacin, 500 mg qid, lovastatin, 20 mg bid, and colestipol, 10 g/bid, were given with dose adjustment for lipid targets and side effects. This was followed by 2 random sequence crossover phases (8 months each) alternating regular niacin with a polygel controlled-release formulation of niacin for use in this regimen. Lipid, lipoprotein, apoprotein, and clinical chemistry determinations were obtained at baseline, during the initial phase, at the 2 crossover phases, and at 6 weeks after therapy. A final questionnaire queried specific side effects and overall preferences. Low-/high-density lipoprotein (LDL/HDL) changed from means of 215/46 mg/dl at baseline, to 94/59 mg/dl after run-in, to 85/52 mg/dl after 8 months of controlled-release niacin, and to 98/56 mg/dl after 8 months of regular niacin (regular niacin vs controlled-release niacin, p <0.005/<0.05). The target of LDL < or = 100 mg/dl was achieved at 8 months by 83% of these patients with controlled-release niacin and by 52% with regular niacin (p <0.01). Compliance was 95% with controlled-release niacin versus 85% with regular niacin (p <0.001). The controlled-release niacin and regular niacin regimens did not differ in terms of uric acid, glucose, insulin, or asparate aminotransferase levels. Overall, 21% of patients called the 3 drugs "very easy" and 72% "fairly easy" to take. The controlled-release niacin-containing regimen was preferred by 21 patients and the regular niacin by 4. In conclusion, these regimens achieve striking lipid changes among hyperlipidemic patients. Controlled release is the preferred niacin preparation in terms of LDL reduction, compliance, patient preference, and achieving the National Cholesterol Education Program guideline of LDL < or = 100 mg/dl. The 2 niacin preparations did not differ in evidence of toxicity.

A comparative review of the adverse effects of treatments for hyperlipidaemia

Various lipid-lowering drugs have been shown to reduce serum cholesterol and serum triglycerides effectively. In view of trials indicating that lipid-lowering drugs may reduce cardiac morbidity and mortality but not the overall mortality in the study group, increased attention must be focused on potential harmful side effects during treatment with these agents. The adverse effects of many of the principal drugs in this category are discussed. Gastrointestinal symptoms, usually self-limited and reversible, are the most common side effects. Potential harmful adverse effects include drug interactions (cholestyramine), myopathy and hepatic injury (HMG-CoA reductase inhibitors), and increased gallstone formation and ventricular arrhythmias (clofibrate). Not all lipid-lowering drugs have been studied adequately on a long term basis, so that medications given for an indefinite period must be reevaluated frequently. However, there are several agents that lower serum lipid levels effectively and that have been used for more than 20 years without serious side effects.

Hyperlipidaemia and hypertension

Hyperlipidaemia and hypertension are commonly found in the population and are independent risk factors for cardiovascular complications. The combined presence of hypertension and hypercholesterolaemia increases considerably the risk for cardiovascular complications. These high-risk patients have to be identified early and treated appropriately in order to avoid complications. The goal of antihypertensive therapy is to reduce the average levels of diastolic pressure to below 90 mm Hg and the systolic pressure to below 140 mm Hg. The goals set for lipid levels in these patients are total cholesterol less than or equal to 200 mg/dl, LDL cholesterol less than or equal to 135 mg/dl and triglycerides less than or equal to 200 mg/dl. The first step in the treatment of patients with both hyperlipidaemia and hypertension is to seek underlying causes and to take appropriate therapeutic measures for both diseases. Non-pharmacological treatment of these high-risk patients includes weight reduction, appropriate dietary measures including alcohol and salt restriction, cessation of smoking and increasing physical activity. If pharmacological antihypertensive treatment is needed, drugs without adverse effects on lipid and lipoprotein levels should be preferred. If, in addition to dietary measures, drug treatment is necessary to reduce high cholesterol levels, bile acid sequestrants are the drug of first choice at present. If long-term safety can be established for HMG CoA reductase inhibitors, these drugs will represent a major advance in the therapy of hypercholesterolaemia.

Treatment of familial hypercholesterolaemia: a controlled trial of the effects of pravastatin or cholestyramine therapy on lipoprotein and apolipoprotein levels

The efficacy and safety of a new, selective inhibitor of cholesterol synthesis, pravastatin, and the bile acid-binding resin, cholestyramine, were compared in a randomized, double-blind study of 120 patients with familial hypercholesterolaemia. After a run-in period of 8-10 weeks with assessment of dietary habits, the patients were treated with pravastatin + placebo, placebo + cholestyramine, or placebo alone. Active pravastatin therapy was initiated with 10 mg b.i.d. for 6 weeks, and was increased to 20 mg b.i.d. for the following 6 weeks. Cholestyramine was given at 24 g d-1, or the highest tolerable dose. After 6 weeks of therapy, serum total and LDL cholesterol levels were reduced by 17% and 21%, respectively, on pravastatin treatment, whereas the corresponding reductions with cholestyramine treatment were 24% and 30%, respectively. With an increased dose of pravastatin, serum and LDL cholesterol concentrations were reduced by 23% and 28%, respectively, after 12 weeks; the effect of cholestyramine was unchanged. HDL cholesterol levels increased in response to pravastatin, by 7% and 9% after 6 and 12 weeks, respectively. Concomitant changes in the concentrations of apolipoproteins B and AI were observed. Three patients discontinued the study because of side-effects: two subjects were treated with pravastatin and one was given placebo. The prevalence of side-effects (including laboratory abnormalities) was 35% for pravastatin, 30% for placebo, and 53% (significantly higher) for cholestyramine. We conclude that pravastatin, in a 40 mg daily dose, is as effective as cholestyramine in lowering LDL cholesterol in familial hypercholesterolaemia. Since the frequency of side-effects is higher with cholestyramine, pravastatin offers a promising alternative for the therapy of this genetic disease.

Lipid lowering in severe familial hypercholesterolaemia: efficacy and safety of a new regenerating system for selective apheresis of apolipoprotein B-containing lipoproteins

Preliminary experience of the efficacy and safety of a new regenerating system for selective extracorporeal removal of apolipoprotein B-containing lipoproteins is described. Four patients with familial hyperlipoproteinaemia were studied on 10 occasions. A system of two, parallel, dextran sulphate cellulose columns was used, and plasma was processed continuously by passage through one of the columns while the other was being regenerated. With this procedure, reductions of very low density and low density lipoprotein cholesterol levels by 73 and 43%, respectively, could be achieved after treatment for 2.5-3 h (1000-3200 ml of plasma volume). No clinically relevant changes in the concentrations of other plasma proteins, including high density lipoproteins, were observed, and the treatment was well tolerated. We conclude that continuous selective apolipoprotein B apheresis is a safe and efficient lipid-lowering procedure which may be used both for metabolic investigations and for studies on possible regression of atherosclerosis.

Combined treatment with cholestyramine and nicotinic acid in heterozygous familial hypercholesterolaemia: effects on biliary lipid composition

In ten patients with heterozygous familial hypercholesterolaemia, combination therapy with cholestyramine and nicotinic acid was instituted for a minimum of 2 months. During therapy, plasma low-density lipoprotein levels were reduced by 32%, and low-density lipoprotein to high-density lipoprotein ratios by 40%. The cholesterol saturation of fasting gall-bladder bile was reduced by 33% during treatment. We conclude that long-term combination therapy with cholestyramine and nicotinic acid is practically feasible in heterozygous familial hypercholesterolaemia, normalizes plasma cholesterol and low-density lipoprotein levels in many patients, and does not result in unwanted side-effects on biliary lipids. It should therefore be considered as the therapy of choice in this condition.

Secondary prevention and lipid lowering: results and implications

In a secondary prevention trial conducted by the National Heart, Lung, and Blood Institute, the effect of lipid lowering by drug intervention on the progression of existing coronary artery disease (CAD) was evaluated in type II hyperlipidemic patients. This first randomized, secondary prevention trial compared the effect of cholestyramine and diet with that of placebo and diet in 143 patients over a 5-year period. End points evaluated were progression or regression of CAD, as demonstrated by angiographic changes compared with baseline angiograms. The cholestyramine-treated group demonstrated a significant reduction in total cholesterol and in low-density lipoprotein cholesterol (LDL) levels as compared with placebo, and an 8% increase in high-density lipoprotein cholesterol (HDL). A statistically significant result supporting the use of cholestyramine treatment was found in one category of CAD progression.

Treatment of common lipoprotein disorders

The pathogenesis of arteriosclerosis is not yet fully understood. The growing body of scientific information strongly indicates that the plasma lipoproteins are playing a crucial role in the development of this disease. We now have conclusive information that dietary cholesterol can produce arteriosclerosis in animals and its removal from the diet can result in regression of these lesions. Most importantly, we know that reducing plasma cholesterol in humans will prevent mortality and morbidity related to the clinical sequelae of arteriosclerosis. A diet can be prescribed that can produce profound reductions in lipoprotein levels in many individuals. The rate of success in achieving modifications that reduce plasma cholesterol is very high. Most patients over time find a diet with reduced cholesterol and saturated fat to be quite palatable. As food suppliers become more active in emphasizing low fat, low cholesterol products, and as restaurants see a demand for healthier entrees, the task for the physician and nutritionist will become much easier. Achieving sustained weight reduction is a much more difficult problem, but this too can be accomplished in many patients if the health professionals maintain a hopeful supportive approach. Ultimately, it is the patient's responsibility to bring about these lifestyle changes. It is the physician's and nutritionist's job to monitor the process and provide sound information and encouragement. For individuals with severe lipoprotein disorders such as familial hypercholesterolemia where diet therapy is helpful but not adequate, the use of medications is now indicated (bile acid binding resins and nicotinic acid). Other medications that promise additional effectiveness and safety are under development (Compactin, Mevinolin). It is our belief that control of coronary heart disease and stroke requires appropriate treatment of lipoprotein disorders and the methods for a strong beginning in this endeavor are at hand.

Dyslipoproteinemia and xanthomatosis

The cutaneous markers associated with dyslipoproteinemia are reviewed in the context of the current view of lipid and lipoprotein metabolism. The utility of determining the plasma levels of lipoproteins and certain apoproteins in children or adults with xanthomas or xanthelasma is discussed. We hope that early identification and appropriate treatment of such patients will reduce the morbidity and mortality from the two major complications of dyslipoproteinemia--atherosclerotic cardiovascular disease and pancreatitis.

Plasma and lipoprotein lipid responses to four hypolipid drugs

The responses of 14 hyperlipidemic subjects to 4 hypolipidemic agents were compared by measuring cholesterol and triglyceride in whole plasma, very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) monthly for 2 months before and 3 months during treatment with each of 4 drugs: clofibrate, 2 g/d; colestipol, 20 g/d; para-aminosalicylic acid-ascorbate (PAS-C), 6-8 g/d; and oxandrolone, 7.5 mg/d. Lipid responses proved to be stable by the first monthly evaluation both off and on each drug. Mean adherence was high and similar for all agents (81-92% of the prescribed dose). Clofibrate was associated with significant decreases in mean plasma cholesterol (-16%, p less than .01), plasma triglyceride (-51%, p less than .005), VLDL-cholesterol (-61%, p less than .005) and VLDL-triglyceride (-61%, P less than .005), while HDL cholesterol increased (+20%, p less than .01), and the LDL-cholesterol/HDL ratio declined (-24%, p less than .05). Colestipol was associated with decreases in mean plasma cholesterol (-15%, p less than .01) and LDL-cholesterol (-22%, p less than .05), while VLDL-triglyceride increased (+41%, p less than .05), and the LDL-cholesterol/HDL-cholesterol radio declined (-25%, p less than .05). PAS-C was associated with decreases in VLDL-cholesterol (-30%, p less than .05), and VLDL-triglyceride (-29%, p less than .05), while the LDL-cholesterol/HDL-cholesterol ratio remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined therapy of niacin, colestipol, and fat-controlled diet in men with coronary bypass. Effect on blood lipids and apolipoproteins

The effects of colestipol (30 grams/day), niacin (7.3 grams/day), and diet on blood lipids and apolipoproteins after one year of therapy are reported. Men selected on the basis of previous coronary artery bypass surgery were randomly assigned to drug or control treatments in an angiographic study of atherosclerosis progression and regression. In 14 men, drugs and diet produced the following changes: Baseline total cholesterol 245 mg/dl, triglyceride 189 mg/dl, and LDL cholesterol 164 mg/dl were decreased by 73 mg/dl (29%), 83 mg/dl (41%) and 69 mg/dl (40%) respectively. Baseline HDL cholesterol, 44 mg/dl was increased 13 mg/dl (33%). Baseline apolipoprotein B, 124 mg/dl and apolipoprotein C-III (heparin precipitate) 5.6 mg/dl were decreased 40 mg/dl (31%) and 2.4 mg/dl (41%) respectively. All these changes are significant, p less than 0.01. Apolipoprotein A-I and apolipoprotein C-III (heparin supernate) were not significantly changed. In the controls, placebo and diet produced no significant decrease in blood lipid or lipoproteins, with the exception that baseline apolipoprotein B, 111 mg/dl increased 18 mg/dl (12%), p less than 0.05.